package com.identify.identifydrawings;

import java.io.Serializable;
import java.security.MessageDigest;

public class SHA1Utils
    implements Serializable {

        /**
         *
         */
        private static final long serialVersionUID = 1L;

        public static String SHA1(String str){
            if(str == null || str.length()==0){
                return null;
            }
            char hexDigits[]={'0','1','2','3','4','5','6','7','8','9','a','b','c','d','e','f'};

            try {
                MessageDigest mdTemp = MessageDigest.getInstance("SHA1");
                mdTemp.update(str.getBytes("UTF-8"));

                byte[] md = mdTemp.digest();
                int j = md.length;
                char buf[] = new char[j*2];
                int k = 0;
                for(int i=0;i<j;i++){
                    byte byte0 = md[i];
                    buf[k++] = hexDigits[byte0 >>> 4 & 0xf];
                    buf[k++] = hexDigits[byte0 & 0xf];
                }
                return new String(buf);
            } catch (Exception e) {
                return null;
            }
        }

    }


